Vibrating motor



April 5, 1938. ERICKSON 2,113,444

VIBRATING MOTOR Filed Sept. 26, 1936 Patented Apr. 5, 1938 UNITED STATESPATENT OFFKIE Prentis E. Erickson, Minneapolis, Minn., assignor to JamesB. Bradshaw, Minneapolis, Minn.

Application September 26, 1936, Serial No. 102,782

1 Claim.

My invention relates to vibration producing apparatus and particularlyto apparatus for imparting vibration to a vibratory tool.

According to common practice many vibratory tools are driven byfollowers reciprocated by cams, by cranks or eccentrics connected to thetool by connecting rods, or by armatures of electric buzzer devices. Allof such tool driving means produce vibratory movement of a substantiallyreciprocatory or rectilinear nature and also are subject to more or lesswear which, after a time, tends to render the device excessively noisy.

A general object of my invention is to provide apparatus for impartingto a vibratory tool a motion including lateral as well as projective andretractive components of movement.

Another object of. my invention is to provide such vibratory tooldriving apparatus of a rotary nature and yet of such construction as toobviate the need for motion converting means such as cam followers,connecting rods and the like.

A more specific object is to provide a vibration producing mechanismutilizing an eccentrically rotating Weight as the vibration producingelement.

Still another object is to provide such mechanism wherein a resilientlysupported motor is vibrated as a unit by an eccentric weight carried bythe shaft of the motor.

A further object is to provide such apparatus of simple, rugged,compact, inexpensive and relatively wear-free construction.

These and other objects and advantages of the invention will more fullyappear from the following description made in connection with theaccompanying drawing, wherein like reference characters refer to thesame or similar parts throughout the various views, and in which:-

Fig. 1 is a top view of an apparatus incorporating an embodiment of myinvention,

Fig. 2 is a side view,

Fig. 3 is a front view, and

Fig. 4 is a sectional view taken along the line 44 of Fig. 2 asindicated by the arrows.

Referring to the drawing, I have illustrated my invention by showing anembodiment thereof incorporated in a scalp massaging device.

Essentially, my vibration producing apparatus consists of a memberjournalled in a suitable bearing element so as to be rotatable about apredetermined axis, said member having a center of mass disposedeccentrically of said axis and said bearing element being mounted onsupporting means therefor of a yieldable nature so as to be resistinglypermissive of lateral displacement of said bearing element and saidmember. Rotation of the eccentrically weighted rotatable member of sucha combination will cause said yieldably supported bearing element tonon-rotatively move in an annular path whereby an object connected tosaid bearing element will be vibrated. A manner in which the abovebroadly described essential elements may be embodied in a scalpmassaging device is as follows.

The illustrated device includes a handle 5, having a radially enlargedportion or head 5a at its forward end carrying forwardly projectingparallel similar extensions 5bspaced from and at respectively oppositesides of the longitudinal axis of the handle 5. The handle 5, head Eaand extensions 5b comprise a support for elements to be described.

Structure including a member journalled in suitable elements issupported from the above described support between and inwardly spacedfrom the extensions 5b thereof. Preferably the supported structureconsists of an electric motor M having a casing or frame 6 and anarmature shaft 1. The motor M is supported from the extensions 5b in amanner permissive of movement of the motor M in directions radialthereof relative to the extensions 512. An endless band 8, of elasticmaterial such as rubber, encircles the extensions 51) and the motor M soas to bear against the outer sides of the extensions 5b and points atright angles thereto on the periphery of the case 6 of the motor. Theband 8 is secured to the extensions 51) and the motor case 6 at itspoints of contact therewith by suitable means such as the screws 9 andID. If. desired washers H and I2 may be placed between the heads of therespective screws 9 and I0 and the band 8.

A spacing block l3, formed of elastic and resilient material such assponge rubber or the like, is interposed between the handle head 5a andthe rear end of the motor M.

To form a motor driven vibration producing unit, an element l4,preferably of cylindrical form and constructed from relatively heavymaterial, is eccentrically mounted on the motor shaft 1, as shown inFig. 4, whereby the rotating parts of the motor M and the element I4together comprise a member having a center of mass disposedeccentrically of the axis of rotation of. such member. The axis ofrotation referred to obviously consists of the longitudinal axis of themotor shaft 1 which is, in a well known manner,

confined to rotation about such axis by shaft bearings (not shown) ofconventional form included in the structure of the motor M in accordancewith common practice.

A cup-like enclosure or housing l5, having a radially outwardlyprojecting annular flange Ia thereon, is placed over the eccentricallymounted weight element l4 and shaft 1 in enclosing and spaced relationthereto and is mounted on the front end of the casing 6 of. the motor Mby suitably securing the flange in to the motor M as by means of nuttedstuds I512. The outer end of the enclosure l5 projects a short distancebeyond the front or free ends of the extensions 5b and carries acentrally located forwardly projecting boss I5c. A strap 16, of elasticmaterial such as rubber, has an apertured medial portion fitting closelyabout the periphery of the boss I50 and secured at its ends to the outerends of the respective extensions 5b by suitable means such as thescrews IT.

The band 8 and strap It constitute elastic connections between the motorM and the extensions 5b of the supporting structure such as to restrainthe case 6 of the motor M from bodily rotation through any appreciableangle and yet resistingly permit deflection of the motor M within limitsin any direction substantially normal to the axis of the motor shaft 1.With such yielding supporting means for the motor, operation of themotor and consequent rotation of the eccentric weight element M willresult in a reaction tending to move the motor M bodily in an annularpath generally normal to the shaft '1. Such movement of the motor M is,of course, not accompanied by rotation of the motor case 6 about theaxis of the shaft 1. The motor M and the housing l5 move together and,in effect, constitute a single body moving annularly as describedrelative to the motor M.

Means is provided for connecting the above mentioned annularly movingbody to any object to be vibrated. To this end an arcuate plate l8a, onwhich a depending, externally screw-threaded attachment stud I8 ismounted, is secured to the lower side of the enclosure l5 as shown inFig. 4.

To illustrate one application of my vibration producing apparatus to avibratory tool or appliance, a scalp massaging appliance S is shownscrew threadedly mounted on the attachment stud [8 in operative relationtherewith. The massaging appliance S is substantially the same as thatshown in my U. S. Patent No. 2,049,434 on Scalp massaging apparatusissued August 4, 1936, and includes a spider-like series of resilientfingers l9 having rubber coverings Mia and.

mounted on the flange 20a of a flanged internally screw-threaded sleeve20 adapted for mounting on the stud it of my device as shown. Curvedelements 2i formed into hooks 2la at their outer ends are secured attheir inner ends to the flange 20, as shown and are adapted forattachment thereto of a suitable retaining strap passing under the chinof a person on whose head the appliance S is disposed.

The motor M is provided with an electric cord 22 extending through asuitable passage within and disposed longitudinally of the handle 5 andadapted to be connected to a source of electrical energy. A switch 23,conveniently mounted in the handle 5, is connected in the circuit of thecord 22 for use in turning the motor M on and off.

The motion applied to the appliance S by the annularly moving motor M isobviously such that the appliance will be vibrated both vertically andhorizontally and will hence produce both a rubbing action and a varyingpressure on the head of the user.

It is apparent that I have invented a novel, simple, compact, effectiveand inexpensive vibration producing apparatus wherein structure subjectto wear and productive of friction is minimized and which is capable ofproducing vibration including components of vibratory motion in variousdirections.

While my vibration producing apparatus has been illustrated anddescribed as applied to a scalp massaging appliance, it should beobvious that the apparatus is readily adapted for use with many othertypes of appliances and tools.

It Will, of course, be understood that various changes may be made inthe form, details, proportions and arrangement of the parts, withoutdeparting from the scope of my invention, which, generally stated,consists in a device capable of carrying out the objects above set forthand in the novel parts and combinations of parts disclosed and definedin the appended claim.

What is claimed is:

Vibration producing apparatus comprising, a motor having a frame and apower delivery shaft projecting outwardly thereof, supporting structurefor said motor, resilient means connecting said motor to said structure,an element mounted on said shaft and having a center of mass disposedeccentrically of said shaft, means secured to said frame and enclosingsaid element and said projecting portion of the shaft, and an elementcarried by said enclosing means and adapted to be connected to an objectto be vibrated.

PRENTIS E. ERICKSON.

